Service manual

displays a 21 read error.
Check Drive Motor.
Fails the performance test and
displays a 27 read error.
Check stop adjust.
Passes performance test to
track 18 then displays 21 read
error.
Check read/write head.
Passes the performance test but
will not load certain programs.
Check stepp
RESISTANCE CHECKS
32 ohms end to centertap
64 ohms end to end
Motor coil = 17 ohms
Tach coil = 175 ohms at rest
Tach coil = 135 - 190 ohms in motion
R/W end to end = 32.4 ohms
R/w end to centertap = 16.3 ohms
Erase coil end to end = 10.5 ohms